The International Nucleotide Database Collaboration (INSDC) have a standardised missing/null value reporting language to be used where a value of an expected format for sample metadata reporting can not be provided.
The controlled vocabulary takes into account different type of constraints. Submitters are strongly encouraged to always provide true values. However, if missing/null value reporting is required, submitters are asked to use a term with the finest granularity for their situation. See the table below for accepted missing value reporting terms.
INSDC Missing Value Reporting Terms:
|INSDC term (top level)||INSDC term (lower level)||Definition|
|not applicable||Information is inappropriate to report, can indicate that the standard itself fails to model or represent the information appropriately|
|missing||not collected||Information of an expected format was not given because it has not been collected|
|not provided||Information of an expected format was not given, a value may be given at the later stage|
|restricted access||Information exists but can not be released openly because of privacy concerns|
Usage of INSDC Missing Value Reporting Terms:
Please use the above standardised missing value vocabulary only if a true value of an expected format for a mandatory field is missing. If a true value is missing for a recommended or an optional field, then these fields should not be used for reporting at all. For any use cases, we discourage the usage of the top level term ‘missing’ and encourage to use a lower level term with a higher granularity to declare the reason for the absence of a true value.
Example of usage:
geographic location (elevation): not collected
geographic location (country and/or sea): restricted access